carbon-language/carbon-lang
1
0
Fork 0
mirror of https://github.com/carbon-language/carbon-lang.git synced 2026-10-03 16:55:55 +01:00
Code Issues Packages Projects Releases 10 Wiki Activity

Add support for C++ pointers to Carbon methods (#7881)

Browse Source 
C++ pointers to Carbon methods are supported using the same mechanisms
as for Carbon functions: we export the method to C++ and then form a
pointer to the exported method. This change does not support invoking a
C++ method pointer from Carbon, which will be more complicated because
we need to model instance binding on the Carbon side.
This commit is contained in:
Geoff Romer
2026-10-02 16:41:55 +00:00
committed by GitHub
parent 632a81fcb6
commit 976692abf4
10 changed files with 1053 additions and 31 deletions
Download Patch File Download Diff File Expand all files Collapse all files
toolchain/check/cpp/export.cpp
+35 -14
View File
@@ -24,6 +24,7 @@
#include "toolchain/check/pattern.h"
#include "toolchain/check/thunk.h"
#include "toolchain/check/type.h"
#include "toolchain/diagnostics/format_providers.h"
#include "toolchain/sem_ir/generic.h"
#include "toolchain/sem_ir/mangler.h"
#include "toolchain/sem_ir/pattern.h"
@@ -165,6 +166,14 @@ auto ExportNameScopeToCpp(Context& context, SemIR::LocId loc_id,
}
}
if (auto* record_decl = llvm::dyn_cast<clang::CXXRecordDecl>(decl_context)) {
// We can't use a class as a name scope until it's complete, so we need to
// ensure it's complete here.
context.clang_sema().RequireCompleteType(
GetCppLocation(context, loc_id),
context.ast_context().getCanonicalTagType(record_decl),
clang::diag::err_incomplete_member_access);
}
return decl_context;
}
@@ -1591,27 +1600,39 @@ auto ExportFunctionToCppPointerConversion(
CARBON_CHECK(!src_clang_decl->isTemplateDecl(),
"can't form a pointer to a template");
const auto* exported_fn_type =
src_clang_decl->getFunctionType()
->getAsCanonical<clang::FunctionProtoType>();
clang::QualType src_fn_type(src_clang_decl->getFunctionType(), /*Quals=*/0);
clang::QualType src_ptr_type;
if (const auto* src_method_decl =
llvm::dyn_cast<clang::CXXMethodDecl>(src_clang_decl);
src_method_decl != nullptr && src_method_decl->isInstance()) {
src_ptr_type = context.ast_context().getMemberPointerType(
src_fn_type, std::nullopt, src_method_decl->getParent());
} else {
src_ptr_type = context.ast_context().getPointerType(src_fn_type);
}
// TODO: consider directly diagnosing things like function pointer/method
// pointer mismatch, or parent type mismatch, rather than deferring them to
// the general pointer type mismatch diagnostic below.
auto dest_function_ptr_type_info =
context.clang_function_pointer_types().Get(dest_type.clang_type_id);
const auto* dest_fn_type =
dest_function_ptr_type_info.clang_type->getPointeeType()
->getAsCanonical<clang::FunctionProtoType>();
clang::QualType dest_ptr_type(dest_function_ptr_type_info.clang_type,
/*Quals=*/0);
if (exported_fn_type != dest_fn_type) {
if (src_ptr_type.getCanonicalType() != dest_ptr_type.getCanonicalType()) {
if (diagnose) {
auto function = context.functions().Get(src_type.function_id);
CARBON_DIAGNOSTIC(ExportedFunctionPtrTypeMismatch, Error,
"can't convert exported function type to `{0}`",
CppType);
CARBON_DIAGNOSTIC(
ExportedFunctionPtrTypeMismatch, Error,
"can't convert exported {0:member |}function pointer to `{1}`",
Diagnostics::BoolAsSelect, CppType);
CARBON_DIAGNOSTIC(ExportedFromFunction, Note,
"function exported with type `{0}`", CppType);
"function exported with pointer type `{0}`", CppType);
context.emitter()
.Build(src_id, ExportedFunctionPtrTypeMismatch, dest_fn_type)
.Note(function.first_decl_id(), ExportedFromFunction,
exported_fn_type)
.Build(src_id, ExportedFunctionPtrTypeMismatch,
src_ptr_type->isMemberFunctionPointerType(), dest_ptr_type)
.Note(function.first_decl_id(), ExportedFromFunction, src_ptr_type)
.Emit();
}
return false;